Motor vehicles and especially trucks, trailers, buses and other heavy vehicles are subject to intensive use of their brakes. It is common practice for truck drivers to overuse their brakes. For example, when traveling downhill, drivers are apt to continually press the brake pedal instead of selecting a lower gear for braking to slow their vehicle. Continuous friction between the brake pad and its drum causes overheating which leads to a loss of efficiency in the braking system. Ultimately, overheating may lead to a partial or complete braking failure and subsequently to a major and fatal road accident.
Heavy vehicles are disproportionately responsible for road accidents. Among these road accidents a significant proportion are due to faulty or incorrect use of the vehicle's brakes. "Brake" accidents may be minimized by early detection and notification to the driver of any abnormal or dangerous situation, such as overheating. Furthermore, driving habits can be improved by tracking and monitoring a driver's braking performance.
Numerous brake detectors and systems for the surveillance of brakes are known. For example, U.S. Pat. No. 4,649,370 to Thompson describes a brake condition indicator which is attachable to a conventional brake shoe. U.S. Pat. No. 5,302,040 to Chen describes a motor vehicle brake detector which is fastened in the brake shoe and includes a blind hole formed in the brake shoe.
U.S. Pat. No. 4,820,057 to Berndt describes a method and apparatus for contactless measuring of the brake temperature of passing railroad cars by fixing sensor apparatus to the rail track to scan the passing wheels.
For maximum efficiency, such stationary detection equipment needs to be placed at regular intervals. Unfortunately, a high percentage of rail vehicles are missed and axle-journal breakages constantly recur.
The known prior art devices require modification of existing braking systems. Such modification tends to be costly and impractical for large vehicle fleets. Additionally, prior art devices are difficult to replace and maintain and are detrimentally affected by oil and dirt.